Providing thin card members having a reading lens associated with a card body such as taught in applicant's U.S. Pat. No. 6,390,372 B1 advantageously provides a compact and low profile device that allows for enhanced viewing through the lens. Such devices may be carried in a wallet or purse similar to a traditional credit card and removed when needed. These reading cards, therefore, require little storage space when not needed as opposed to the much larger space needed to store reading glasses in one's purse or pocket.
Other cards include a Fresnel lens as generally disclosed in U.S. Pat. Nos. 6,769,618 B1 to Finkelstein; 6,176,430 B1 to Finkelstein et al.; and 5,434,405 to Finkelstein et al. The Fresnel lens can be formed integrally with the card base. The Fresnel lens can be stamped into the card body using a hot stamping die or from material that is poured into a cavity removed from the card base. As discussed in applicant's U.S. Pat. No. 6,390,372, which is incorporated by reference as if reproduced in its entirety herein, Fresnel lenses generally do not provide suitable viewing enhancement for reading purposes as the primary focus is magnification rather than vision correction. In this regard, Fresnel lenses generally have poor optics in terms of the resolution they provide creating blurring or distortion of the text to be read. Also, Fresnel lenses typically do not have a well-defined diopter rating which can vary sometime in the range of between four and six, which generally is more magnification than is necessary for reading lenses. Another drawback is that manufacture of Fresnel lenses usually requires a soft plastic material such as PVC for being pressed to form the concentric stepped grooves and ridges of these lenses. This softer lens material is not desirable for lenses incorporated into thin cards as they are likely to be damaged due to the handling they are intended to undergo. To this end, the '618 patent teaches recessing the Fresnel lens surface features from the adjacent surface of the card body.
Using lenses with well-defined diopter ratings is known for providing reading cards as taught in applicant's '372 patent. However, in these cards the lenses and the body of the card are separate components such that an opening in the body needs to be provided for receipt of the lens therein. This may cause an undesirable amount of flexibility in the relatively thin card body. Further, the interface between the edges about the opening at the peripheral edges of the lens needs to be carefully sized and configured to securely hold the lens to the card body. Accordingly, undue bending of the flexible card such as can occur when a user is sitting with the card carried in their back pocket may cause the lens to pop out or otherwise become dislodged from the card opening.
Providing lights on thin card members advantageously provides compact and low profile lighting devices for users thereof. However, known light cards are generally deficient in the switching mechanisms utilized to selectively power the lights carried thereby. Generally, when employing LEDs that include elongate positive and negative wire leads extending therefrom, it is known that mechanical stress on the leads should be avoided. However, where such LEDs are employed with lighted cards, there are switching mechanisms thereof that have required that one of the wire leads be bent each time the LED light is to be turned on (see U.S. Pat. No. 5,457,613 to Vandenbelt et al. and U.S. Pat. No. 6,070,990 to Dalton et al.). In addition to the undue stress on the LED leads generated by the switching mechanisms taught by the '613 and '990 patents, the '990 patent also teaches a tray-type card body having a thinned wall area aligned with the LED lead to be bent. The thinning of this wall portion allows it to be flexible so that a user can push on the wall portion and bend both it and the LED lead. As is apparent, both of these features are undesirable for the switching function in which they are implemented as it is anticipated that the light switch may be actuated thousands of times over the life of a light card. As such, this constant bending of the LED lead wire may ultimately cause premature failure of the LED. Similarly, where the main wall of the card also is thinned and constantly bent for switching the light on, there is the possibility that the thinned wall will fail over repeated cycling.